plotting plane & a triangle

*To*: mathgroup at smc.vnet.net*Subject*: [mg91340] plotting plane & a triangle*From*: skunkwerk <skunkwerk at gmail.com>*Date*: Sat, 16 Aug 2008 05:54:56 -0400 (EDT)

Hi, i'm working on developing some 3d software and I was hoping to use mathematica to test the results of some of my code. Specifically, I'm trying to visualize a plane and a triangle, to see if they intersect, and if not, which side of the plane the triangle's points are on (I'm calculating this using algebra, and need to check the results) so far I've done: (the triangle) pl1 = Graphics3D[{Polygon[{{-80.2576, -594.271, 224.043}, {-120.608, -588.635, 221.101}, {1.32756, -598.31,261.244}}]}] (the plane) pl2 = Plot3D[0.402395*x - 0.899308*y + 0.171241*z + 274.122 = 0,{x, -10000, 10000}, {y, -10000, 10000}] then: Show[pl1, pl2] questions: 1) the Polygon is displayed fine on its own, but the plane looks completely flat along z=0 and is axis-aligned, so I'm not sure what's wrong... 2) the final "Show" command results in a really flat graph that doesn't show me anything... do I need to increase or fix the range? any help would be much appreciated thanks imran